Thermal module

ABSTRACT

A thermal module includes a blower, a fin unit and a heat pipe. The blower includes a housing and an impeller received in the housing. The housing defines an air inlet and an air outlet perpendicular to the air inlet. The fin unit is arranged at the air outlet of the blower. The heat pipe includes a tube defining a chamber, and a wick structure disposed in the chamber. The heat pipe forms an evaporation section and a condensation section attaching to the fin unit. At least one contacting member is depressed inwardly from the evaporation section of the heat pipe for accommodating an electronic component therein. A depth of the chamber at the at least one contacting member is less than that at other portion of the evaporation section of the heat pipe without the at least one contacting member.

BACKGROUND

1. Technical Field

The disclosure generally relates to thermal modules, and moreparticularly to a thermal module incorporating a plate type heat pipe.

2. Description of Related Art

With continuing development of the electronic technology, electroniccomponents such as CPUs are generating more and more heat which isrequired to be dissipated immediately. A thermal module is usuallyadopted for cooling the electronic component.

Generally, the thermal module includes a blower for generating forcedairflow, a fin unit arranged at an air outlet of the blower, and a heatpipe. The heat pipe includes an evaporating section attached to theelectronic component to absorb heat therefrom, and a condensing sectionattached to the fin unit to transfer the heat of the electroniccomponent to the fin unit. Thus the forced airflow of the blower cantake away the heat after flows through the fin unit. However, most ofelectronic devices that contain electronic components therein, such as alaptop computer, do not have enough space therein, and thus a size ofthe heat pipe is usually limited. Accordingly, a heat transfercapability of the heat pipe is limited, which means that the heat of theelectronic component can not be timely transferred to the fin unit fordissipation.

For the foregoing reasons, therefore, there is a need in the art for athermal module which overcomes the limitations described.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric, assembled view of a thermal module according toan exemplary embodiment.

FIG. 2 is an isometric, exploded view of the thermal module of FIG. 1.

FIG. 3 is a cross sectional view showing the thermal module of FIG. 1assembled onto an electronic component.

FIG. 4 is similar to FIG. 3, but shows a thermal module with analternative heat pipe.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 3, a thermal module for cooling pluralelectronic components 90 which are mounted on a circuit board 80 of anelectronic device is shown, including a blower 10, a fin unit 20 and aheat pipe 30. In FIG. 3, although only one electronic component 90 isshown for simplifying the drawings, it is to be understood that otherelectronic components 90 not shown in FIG. 3 can be assembled to thethermal module in the same way for cooling.

Referring to FIG. 2, the blower 10 is for generating forced airflow, andincludes a fan housing 12 and an impeller 14 rotatably received in thefan housing 12. A circular air inlet 120 is defined in a top side of thefan housing 12. An air outlet 122 is defined in a lateral side of thefan housing 12. The air outlet 122 is rectangular, and is perpendicularto the air inlet 120. The fin unit 20 is arranged at the air outlet 122of the blower 10. The fin unit 20 includes a plurality of fins 22stacked together. A channel 24 is defined between neighboring fins 22and communicates with the air outlet 122.

The heat pipe 30 is in plate type, and has a profile substantially beingZ-shaped. The heat pipe 30 forms an evaporation section 31 and acondensation section 33 at two ends thereof, respectively. Theevaporation section 31 is attached to the electronic components 90 toabsorb heat therefrom. The condensation section 33 is linear-shaped, andattaches to the fin unit 20. The heat of the electronic components thuscan be transferred to the fin unit 20 by the heat pipe 30 fordissipation.

The evaporation section 31 of the heat pipe 30 is substantiallyL-shaped, and includes an elongated portion 312 extendingperpendicularly from an end of the condensation section 33, and an endportion 314 extending perpendicularly from the elongated portion 312.The end portion 314 is parallel to the condensation section 33. The endportion 314 and the condensation section 33 are respectively located atopposite sides and opposite ends of the elongated portion 312 of theheat pipe 30. A plurality of through holes 38 are defined in theevaporation section 31 of the heat pipe 30 for fixing members, such asscrews to extend therethrough and be secured to the circuit board 80,thus to assemble the thermal module onto the electronic components 90.

Referring to FIG. 3, the heat pipe 30 includes a sealed tube 37, a wickstructure 39 and a working fluid. The tube 37 is made of metal with highheat conductivity coefficient, such as copper or its alloy. The tube 37includes a top plate 36, a bottom plate 32 and a side plate 34interconnecting outer peripheries of the top plate 36 and the bottomplate 32. Cooperatively the top plate 36, the bottom plate 32 and theside plate 34 define a vacuum chamber 35 in the tube 37. The workingfluid is filled in the chamber 35, and has a relatively lower pressureand boiling point. The wick structure 39 is disposed in the chamber 35of the heat pipe 30 soaked with the working fluid. A plurality of poresare defined in the wick structure 39 to generate a capillary force tothe working fluid.

Referring to FIG. 2 again, the top plate 36 of the heat pipe 30 includesthree portions, i.e., a first portion 330 at the condensation section 33of the heat pipe 30, a second portion 369 at the elongated portion 312of the evaporation section 31, and a third portion 367 at the endportion 314 of the evaporation section 31. The first portion 330 isplanar and attaches to a bottom side of the fin unit 20 closely, whilstthe second portion 369 and the third portion 367 of the top plate 36 areused to contact the electronic components 90.

The second portion 369 and the third portion 367 of the top plate 36form a plurality of contacting members 360 depressed downwardlytherefrom for accommodating the electronic components 90 therein.Shapes, sizes, and positions of the contacting members 360 are decidedaccording to an arrangement of the electronic components 90. Theplurality of contacting members 360 can have different shapes, areas anddepths. In this embodiment, four separated contacting members 360 areshown, in which one contacting member 360 is defined in the thirdportion 367 of the top plate 36, i.e., at the end portion 314 of theevaporation section 31, and the other three contacting members 360 aredefined in the second portion 369 of the top plate 36, i.e., at theelongated portion 312 of the evaporation section 31. Thus the heat pipe30 can be used to absorb heat from four electronic components 90 at thesame time.

Each contacting member 360 is located at a middle of the top plate 36,with a width smaller than that of the evaporation section 31 of the heatpipe 30. Two opposite lateral sides, i.e., left and right sides of eachcontacting member 360 respectively space a distance from the side plate34 of the tube 37 of the heat pipe 30. Each of the contacting members360 includes a base 361 and a flange 362 around the base 361. The base361 is substantially square or rectangular, and is lower than the topplate 36 of the heat pipe 30. The flange 362 is perpendicular to thebase 361, and connects the base 361 to the top plate 36 of the heat pipe30. A concave 363 is defined in the top plate 36 above each base 361 andsurrounded by a corresponding flange 362. Thus, a depth of the chamber35 of the heat pipe 30 at the contacting members 360 is less than thatat other portion of the evaporation section 31 of the heat pipe 30without the contacting members 360.

In this embodiment, the wick structure 39 is sintered powders. The wickstructure 39 is arranged in the middle of the chamber 35 of the heatpipe 30. A width of the wick structure 39 is smaller than that of theheat pipe 30, but larger than that of each of the contacting members360. The wick structure 39 includes a planar bottom side attaching tothe bottom plate 32 of the tube 37 of the heat pipe 30, and a non-planartop side attaching to the top plate 36 of the tube 37. Four recesses aredefined in the top side of the wick structure 39 receiving thecontacting members 360 of the top plate 36 therein. Thus the wickstructure 39 covers the contacting members 360 entirely, including thebases 361 and the flanges 362, and covers a portion of the top plate 36around the contacting members 360. A passage 60 is defined between eachlateral side of the wick structure 39 and the side plate 34 of the tube37 of the heat pipe 30.

When assembled, the top side of the condensation section 33 of the heatpipe 30 attaches to the bottom side of the fin unit 20 directly. Theelectronic components 90 are attached to the top plate 36 of theevaporation section 31 of the heat pipe 30 at the contacting members360. Each electronic component 90 enters into a corresponding concave363, with an outer surface 92 thereof attaching to a corresponding base361 closely. Therefore, the electronic components 90 are partly receivedin the concaves 363 of the heat pipe 30. Other part of the heat pipe 30without the contacting members 360 extend toward the circuit board 80 tobe adjacent to the circuit board 80. Therefore, spaces around theelectronic components 90 are utilized to accommodate the heat pipe 30,and a size, particularly a thickness, of the heat pipe 30 is increased,whilst a size of the electronic device which incorporates the thermalmodule does not need change.

During operation, the working fluid in the wick structure 39 of the heatpipe 30 absorbs the heat generated by the electronic components 90 andevaporates. Then the vapor moves to the condensation section 33 alongthe passages 60 at the lateral sides of the wick structure 39 to releasethe heat thereof to the fin unit 20. The vapor cools and condenses atthe condensation section 33. The condensed working fluid returns to theevaporation section 31 by the capillary force of the wick structure 39,and evaporates into vapor again thereat. Since the heat pipe 30 of thethermal module has an enlarged size, a heat transfer capability of theheat pipe 30 is enhanced, whereby the heat of the electronic components90 can be continuously and timely transferred to the fin unit 20 by theheat pipe 30. Finally the airflow of the blower 10 flowing across thefin unit 20 can take away the heat to an outside. Therefore, the thermalmodule can cool plural electronic components 90 simultaneously. Autilization efficiency of the thermal module is accordingly enhanced.

FIG. 4 shows a thermal module with an alternative heat pipe 50. Thedifference between this heat pipe 50 and the previous heat pipe 30 isthe wick structure 59. In this embodiment, the wick structure 59 has awidth substantially equaling to that of the chamber 55 of the heat pipe50, and abuts the side plate 54 of the tube 57 at lateral sides thereof.The wick structure 59 is substantially U-shaped, includes a main body590 and a pair of protrusions 592 extending upwardly from lateral sidesof the main body 590, respectively. The main body 590 has a thicknessequaling to a depth of the chamber 55 of the heat pipe 50 at thecontacting members 560. A bottom side of the main body 590 abuts thebottom plate 52 of the heat pipe 50, and a top side of the main body 590of the wick structure 59 abuts the bases 561 of the contacting members560. Other portion of the top plate 56 around the contacting members 560is spaced from the main body 590. The protrusions 592 extend from thetop side of the main body 590 to abut lateral sides of the top plate 56adjacent to the side plate 54 of the tube 57 of the heat pipe 20. Apassage 70 is defined between the pair of protrusions 592 over the mainbody 590 for movement of the vapor. The contacting members 560 arelocated in the passage 70.

It is to be understood, however, that even though numerouscharacteristics and advantages of the disclosure have been set forth inthe foregoing description, together with details of the structure andfunction of the disclosure, the disclosure is illustrative only, andchanges may be made in detail, especially in matters of shape, size, andarrangement of parts within the principles of the disclosure to the fullextent indicated by the broad general meaning of the terms in which theappended claims are expressed.

1. A thermal module, comprising: a blower comprising a housing and animpeller received in the housing, the housing defining an air inlet andan air outlet perpendicular to the air inlet; a fin unit arranged at theair outlet of the blower; and a heat pipe comprising a tube defining achamber therein, and a wick structure disposed in the chamber of thetube, the heat pipe forming an evaporation section and a condensationsection at opposite ends of the tube, respectively, the condensationsection attaching to the fin unit, at least one contacting memberdepressed inwardly from the evaporation section of the heat pipe foraccommodating an electronic component therein, a depth of the chamber atthe at least one contacting member being less than that at other portionof the evaporation section of the heat pipe without the at least onecontacting member.
 2. The thermal module of claim 1, wherein the atleast one contacting member comprises a base depressed in the tube and aflange extending upwardly from a periphery of the base, and the base hasone of rectangular shape and square shape and adapted for contacting theelectronic component.
 3. The thermal module of claim 2, wherein the tubecomprises a first plate, a second plate parallel to the first plate, anda side plate interconnecting the first plate and the second plate, theat least one contacting member being formed on the first plate, the wickstructure comprising a main body and a pair of protrusions, the mainbody contacting the second plate and the first plate at the at least onecontacting member, the protrusions extending from the main body to abutthe first plate at a position spaced from the at least one contactingmember.
 4. The thermal module of claim 3, wherein a width between theprotrusions is larger than a width of the base, the protrusions beingspaced from the flange of the at least one contacting member, a channelbeing formed between the pair of protrusions.
 5. The thermal module ofclaim 4, wherein a width of the main body of the wick structuresubstantially equals to that of the chamber of the tube, the protrusionsextends from lateral sides of the main body and attaching to the sideplate of the tube.
 6. The thermal module of claim 2, wherein the tubecomprises a first plate, a second plate parallel to the first plate, anda side plate interconnecting the first plate and the second plate, theat least one contacting member being formed on the first plate, the wickstructure contacting the second plate and the first plate at the atleast one contacting member, the wick structure covering the base andthe flange of the at least one contacting member.
 7. The thermal moduleof claim 6, wherein a width of the wick structure is smaller than thatof the chamber, a passage is defined between the wick structure and theside plate of the tube.
 8. The thermal module of claim 1, wherein theheat pipe is substantially Z-shaped, the condensation section of theheat pipe being linear-shaped, the evaporation section of the heat pipebeing L-shaped.
 9. The thermal module of claim 1, wherein a plurality ofcontacting members are formed on the evaporation section of the heatpipe.
 10. A heat pipe, comprising: a tube defining a chamber therein;and a wick structure disposed in the chamber of the tube; wherein theheat pipe respectively forms an evaporation section and a condensationsection at opposite ends of the tube, at least one contacting memberdepressed inwardly from the evaporation section of the heat pipe foraccommodating an electronic component therein, a depth of the chamber atthe at least one contacting member being less than that at other portionof the evaporation section of the heat pipe without the at least onecontacting member.
 11. The heat pipe of claim 10, wherein the at leastone contacting member comprises a base in the tube and a flangeextending outwardly from a periphery of the base to connect with anoutside of the tube, and the base is one of square-shaped andrectangle-shaped.
 12. The heat pipe of claim 11, wherein the tubecomprises a first plate, a second plate parallel to the first plate, anda side plate interconnecting the first plate and the second plate, theat least one contacting member being formed on the first plate, the wickstructure comprising a main body and a pair of protrusions, the mainbody contacting the second plate and the first plate at the at least onecontacting member, the protrusions extending from the main body to abutthe first plate at a position spaced from the at least one contactingmember.
 13. The heat pipe of claim 12, wherein a width between theprotrusions is larger than a width of the base, the protrusions beingspaced from the flange of the at least one contacting member, a channelbeing formed between the pair of protrusions.
 14. The heat pipe of claim13, wherein a width of the main body of the wick structure substantiallyequals to that of the chamber of the tube, the protrusions extends fromlateral sides of the main body and attaching to the side plate of thetube.
 15. The heat pipe of claim 11, wherein the tube comprises a firstplate, a second plate parallel to the first plate, and a side plateinterconnecting the first plate and the second plate, the at least onecontacting member being formed on the first plate, the wick structurecontacting the second plate and the first plate at the at least onecontacting member, the wick structure covering the base and the flangeof the at least one contacting member.
 16. The thermal module of claim15, wherein a width of the wick structure is smaller than that of thechamber, a passage is defined between the wick structure and the sideplate of the tube.
 17. The heat pipe of claim 10, wherein the heat pipeis substantially Z-shaped, the condensation section of the heat pipebeing linear-shaped, the evaporation section of the heat pipe beingL-shaped, a plurality of contacting members being formed on theevaporation section of the heat pipe.